Conventionally, nursing consumables such as gauze, urinary pad, diaper, replacement sheets etc., has no sensing functions, and therefore cannot notify the active conditions of the nursing consumables or notify the care receivers as well as the caregivers to change the nursing consumables when become dirty. In addition, the conventional nursing consumables do not have physiological sensing functions, either. In generally, some care receivers such as infants, elderly with dementia or patients with limited mobility, may not be able to self-control their excretions. Therefore, it is common among care receivers to wear diapers to lessen the burden of the caregivers.
However, moisture in diaper, PH of urine, and proteins or bacteria in feces tend to cause skin-related infections among diapered care receivers. Therefore, it is quite important for caregivers to determine whether diapers are dirty and when to change dirty diapers, as well as to predict when the care receivers might urinate or excrete. Conventionally, the determination of timing to change diapers is realized based on caregivers actively and physically touching the diaper, thereby sensing whether the humidity inside the diaper is too high. Alternatively, caregivers would passively wait until the care receivers express discomfort. However, the aforementioned judgments depend primarily on personal experiences or feelings of the caregivers, and the caregivers may judge incorrectly when the care receivers give uncertain expressions.
As a result, smart diapers capable of sensing the presence of excretions have been developed. Generally, a conventional smart diaper has a conductive tape formed by printing conductive resins on a waterproof layer of the smart diaper. The conductive tape is covered with a water-absorbing layer, and a transceiver assembly is used to sense the impedance changes of the conductive tape. When the water-absorbing layer absorbs certain amount of urine, some of the urine may permeate to the conductive tape and consequently the conductive tape has an impedance change. Therefore, once the transceiver assembly senses that the impedance of the conductive tape has changed, it would notify that the water-absorbing layer has absorbed certain amount of urine and it is time to change a new smart diaper.
Conventionally, the waterproof layer is made smooth so that the conductive resins can be printed thereon and the connection between the waterproof layer and the transceiver assembly can be realized more easily. However, because feces could not permeate to the conductive tape through the water-absorbing layer, the conductive tape would not have an impedance change even when the care receiver has excreted. Therefore, the determination of diaper change for the care receiver still relies on the caregiver's attention. Moreover, convention smart diapers can only notify the caregivers when to change but not sense or analyze each urination of the care receivers.